The present invention relates to optical analysis systems and methods for analyzing fluids and, in particular, to systems and methods for analyzing the properties of a fluid cement composition.
Fluid cement compositions like dry cement blends and cement slurries can be complex fluid systems where variations from a precise formulation can result in a plurality of detrimental outcomes including, but not limited to, (1) failing to provide zonal isolation, thereby allowing undesirable fluids to enter the wellbore, which in severe instances may yield well blowouts, (2) exceeding fracture pressures, thereby causing wellbore and formation damage, (3) producing an unpredictable setting time, which may result in premature setting in an undesired location or excessive setting times that delay subsequent operations, and/or (4) causing inhomogeneous setting reactions, which can result in reduced mechanical integrity of the set cement composition. Remediating the various detrimental outcomes can prove to be costly and time consuming, and in some severe cases have significant environmental impact.
Variations in the precise formulation of an otherwise properly designed fluid cement composition (i.e., having all the request components in the proper amounts) can arise from, inter alia, compositional inhomogeneity throughout the fluid cement composition. Most often compositional inhomogeneity arises from particulate segregation and variations in cement-to-water ratios. For example, dry cement blends often include cement particles and filler particles of various sizes and specific gravities and, in some instances, chemicals in a fine powder form. Long-term storage and transportation of such a dry cement blend can cause the particles to separate based on, inter alia, density, size, and shape. To mitigate inhomogeneity in dry cement blends, an extensive mixing process of small batches of dry cement blend are performed. In many instances the mixing processes are in excess of what is needed, which consumes time and energy, thereby driving up costs.
In cement slurries, for example, density variations in the cement slurry can be a common problem in addition to compositional inhomogeneity described above. Density variations lead to unpredictable setting times. Further, density variation can cause a mismatch between the slurry and the pressure of the formation, which can lead to formation fluids entering the wellbore or slurry loss into the formation.
Monitoring the homogeneity and/or setting status of cement fluid compositions may enable the mitigation of the detrimental outcomes and costly remedial operations associated therewith. However, in relation to wellbore operations, such monitoring should be remote and robust to the chemicals and temperatures found in a subterranean formation. Well logging operations, which can add significant nonproductive time and cost to a cementing operation, are the primary avenue to downhole analysis.
Accordingly, in situ monitoring of cement fluid compositions may not only provide higher quality control in cementing operations but may also reduce the cost and mitigate the need for remedial operations.